That coast looks pretty neat, and I am sure the long rendertime is caused by the RT reflection on the wet beach. If you could flatten the sand grains there, it would be quicker. And perhaps even more natural, like a thin film of water over the sand. Perhaps also decrease reflectivity to 60% or so. And also some variation in the sand may be good to implement, or just a fractal warp.

Position 4 (angled and trailing a flock of pelicans) - and had one of those 'oh crap' moments when I realized the veggie covering didn't extend far enough down the beach toward the hill, and also saw that the wave coverage was imperfect. Back to the rendering board.....Durn